It’s an absolutely sweltering day. You and the kids have been busy running errands and everyone is cranky. (Yes, even you.) The whole family can’t wait to get home, slip on your swimsuits and hop into the pool for a cool, refreshing and calming swim. By the time you get home, the kids are jumping up and down and you’re fairly twitching with your need to drift on a raft with a cool drink and a good book while the kids play.
Finally, everyone runs outside. But just as you’re about to jump in, you get a look at the pool. It is … gross. This is a disaster. And it’s one that could have been avoided if you’d only taken proper care of your pool filter. Proper filtration is critical to maintaining a crystal clear, safe pool.
There are three types of pool filters, and they’re all relatively easy to care for:
Cartridge Filters – Cartridge filters can be composed of a number of materials. Some may be made from wound strands of a material such as polypropylene. Your pool water passes through a fine filter that captures sediment, metals and some microorganisms from the water. As cartridge filters are not backwashed, they are simply cleaned or replaced once they become dirty or block. The frequency of changing depends on the quality of the water passing through the filter.
For basic maintenance, simply remove and rinse off your filter with a hose every once in a while. For a deeper cleaning, it is best to use a filter cleaner which is sprayed onto the cartridge and chemically assists in removing debris, body oils, suntan lotions, etc. at least once per season. We recommend this cleaning as you’re putting your pool to bed for the winter unless you’re planning on replacing your cartridge in the spring. To keep your pool its cleanest, though, you’ll need to replace the filter every 3-5 years.
Sand Filters – Sand filters are large tanks with a bed of special sand in the bottom. Your pool water enters through the top of the tank and as gravity pulls it through the sand, impurities are trapped. Filtered water flows back out the bottom of the tank and returns to your pool.
As more dirt and debris are trapped, pressure in the tank will rise and the filter will need to be periodically backwashed. You can tell when it’s time to do this by watching the pressure gauge on the tank. Sand filters should be backwashed when the pressure rises 8-10 psi above normal operating pressure and after every vacuum.
On average, sand should be replaced every 3–5 years. The jagged edges of the sand wear down and become smooth as the sand ages. When this happens the sand can no longer trap debris particles and dirt can pass through the sand and back into the pool.
Diatomaceous Earth Filters – DE is a very fine powder made from the crushed exoskeletons of fossilized diatoms – sort of like an ancient algae. The porous material makes an excellent filter and is used here to coat a fabric-covered filter grid.
Like any filter, a D.E. filter will need to be cleaned. Over time, the D.E. will trap dirt and other contaminants from your pool just as they are supposed to do. If they become too clogged, they can’t do their job.
In addition to knowing how to do it, you need to know when to do it. In most cases, you will need to perform regular backwashes and replacement of the D.E. On top of that, you will also need to remove and completely clean the filter.
Here is when you should do it:

  • Backwash and replace your D.E. when the pressure gauge rises 8 – 10 psi above normal.
  • Backwash and replace your D.E. once a month if your pool is getting regular use.
  • Completely clean the filter at least once a year and sometimes twice a year depending on usage.

Save yourself the heartbreak of a yucky pool. Keep up with your filter maintenance – or let us do it for you!